Patient specific alignment guide with cutting surface and laser indicator

ABSTRACT

A patient-specific guiding system for guiding an instrument relative to a portion of an anatomical feature of a patient. The patient-specific guiding system includes a patient-specific guide. The guide includes a first portion having a first patient-specific inner surface that conforms to a first surface of the anatomical feature and an outer surface opposite the first patient-specific inner surface. The first portion also includes a guide surface for use in guiding the instrument relative to the anatomical feature. The guide also includes a second portion having a second patient-specific inner surface that conforms to a second surface of the anatomical feature and an outer surface opposite the second patient-specific inner surface. The second portion is removably connected to the first portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.12/389,901, filed Feb. 20, 2009, which is a continuation-in-part of U.S.application Ser. No. 12/211,407, filed Sep. 16, 2008, which is acontinuation-in-part of U.S. application Ser. No. 12/039,849, filed Feb.29, 2008, which: (1) claims the benefit of U.S. Provisional ApplicationNo. 60/953,620, filed on Aug. 2, 2007, U.S. Provisional Application No.60/947,813, filed on Jul. 3, 2007, U.S. Provisional Application No.60/911,297, filed on Apr. 12, 2007, and U.S. Provisional Application No.60/892,349, filed on Mar. 1, 2007; (2) is a continuation-in-part U.S.application Ser. No. 11/756,067, filed on May 31, 2007, which claims thebenefit of U.S. Provisional Application No. 60/812,694, filed on Jun. 9,2006; (3) is a continuation-in-part of U.S. application Ser. No.11/971,390, filed on Jan. 9, 2008, which is a continuation-in-part ofU.S. application Ser. No. 11/363,548, filed on Feb. 27, 2006; and (4) isa continuation-in-part of U.S. application Ser. No. 12/025,414, filed onFeb. 4, 2008, which claims the benefit of U.S. Provisional ApplicationNo. 60/953,637, filed on Aug. 2, 2007.

In addition, this application is a continuation-in-part of U.S.application Ser. No. 12/486,992, filed Jun. 18, 2009.

Also, this application is a continuation-in-part of U.S. applicationSer. No. 12/103,834, filed Apr. 16, 2008, which claims the benefit ofU.S. Provisional Application No. 60/912,178, filed Apr. 17, 2007.

This application is also a continuation-in-part of U.S. application Ser.No. 12/483,807, filed on Jun. 12, 2009, which is a continuation-in-partof U.S. application Ser. No. 12/371,096, filed on Feb. 13, 2009, whichis a continuation-in-part of U.S. application Ser. No. 12/103,824, filedon Apr. 16, 2008, which claims the benefit of U.S. ProvisionalApplication No. 60/912,178, filed on Apr. 17, 2007.

The disclosures of the above applications are incorporated herein byreference.

FIELD

The following relates to an alignment guide for implantation of aprosthesis and, more particularly, to a patient-specific alignment guidewith a cutting surface. The alignment guide may also include a laserindicator.

INTRODUCTION

Various custom made, patient-specific orthopedic implants and associatedtemplates and guides are known in the art. Such implants and guides canbe developed using commercially available software. Custom implantguides are used to accurately place pins, guide bone cuts, and insertimplants during orthopedic procedures. The guides are made from apre-operative plan formed from an MRI or CT scan of the patient.

The present teachings provide patient-specific alignment guides that canconveniently and accurately position a cutting tool relative to ananatomical feature.

SUMMARY

A patient-specific guiding system for guiding an instrument relative toa portion of an anatomical feature of a patient is disclosed. Thepatient-specific guiding system includes a patient-specific guide. Theguide includes a first portion having a first patient-specific innersurface that conforms to a first surface of the anatomical feature andan outer surface opposite the first patient-specific inner surface. Thefirst portion also includes a guide surface for use in guiding theinstrument relative to the anatomical feature. The guide also includes asecond portion having a second patient-specific inner surface thatconforms to a second surface of the anatomical feature and an outersurface opposite the second patient-specific inner surface. The secondportion is removably connected to the first portion. The first andsecond patient-specific inner surfaces each have a three dimensionalcontour that nests and closely conforms to the first and secondsurfaces, respectively, of the anatomical features, to align the guiderelative to the anatomical feature.

Also, a method of guiding an instrument relative to an anatomicalfeature of a patient is disclosed. The method includes nesting apatient-specific guide that includes a first portion and a secondportion on the anatomical feature by fitting a patient-specific innersurface of the first portion to a first surface of the anatomicalfeature and by fitting a patient-specific inner surface of the secondportion to a second surface of the anatomical feature. The method alsoincludes securing the first portion to the anatomical feature, removingthe second portion from the first portion, and leaving the first portionsecured to the anatomical feature. Furthermore, the method includesguiding the instrument with a guide surface of the first portionrelative to the anatomical feature.

Still further, a patient-specific guiding system for guiding aninstrument relative to an anatomical feature of a patient is disclosed.The patient-specific guiding system includes a patient-specific guidewith a patient-specific inner surface. The patient-specific innersurface has a three-dimensional contour that closely conforms to asurface of the anatomical feature. The patient-specific guide has aguide surface that guides the instrument relative to the anatomicalfeature. Furthermore, the system includes a laser coupled to the guidethat emits a light that identifies a reference plane for use in aligningthe guide surface relative to the anatomical feature.

Additionally, a method of guiding an instrument relative to ananatomical feature is disclosed. The method includes nesting apatient-specific guide on the anatomical feature by fitting apatient-specific inner surface of the guide to a surface of theanatomical feature. The guide includes a guide surface that guides theinstrument relative to the anatomical feature. The method also includessecuring the guide to the anatomical feature, emitting a laser lightthat identifies a reference plane for use in aligning the guide surfacerelative to the anatomical feature, and guiding the instrument relativeto the reference plane.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 a perspective view of a patient-specific guiding system having apatient-specific alignment guide according to various exemplaryembodiments of the present teachings;

FIG. 2 is a sectional view of the alignment guide of FIG. 1 coupled toan anatomical feature;

FIG. 3 is a sectional view of a portion of the alignment guide of FIG. 1shown prior to cutting the anatomical feature;

FIG. 4 is a perspective view of the patient-specific alignment guideaccording to various other exemplary embodiments of the presentteachings;

FIG. 5 is a top view of the patient-specific alignment guide accordingto various other exemplary embodiments of the present teachings;

FIG. 6 is a side view of the alignment guide of FIG. 5;

FIG. 7 is a sectional view of a patient-specific guiding systemaccording to various other exemplary embodiments of the presentteachings;

FIG. 8A is a sectional view of the system of FIG. 7 shown prior tocutting an anatomical feature;

FIG. 8B is a top view of the system of FIG. 7 shown with a secondarycutting block mounted to the alignment guide;

FIG. 9 is a sectional view of a patient-specific guiding systemaccording to various other exemplary embodiments of the presentteachings;

FIG. 10 is a perspective view of a patient-specific guiding systemaccording to various other exemplary embodiments of the presentteachings;

FIG. 11 is a front view of a patient-specific guiding system accordingto various other exemplary embodiments of the present teachings;

FIG. 12 is a perspective view of a patient-specific guiding systemaccording to various other exemplary embodiments of the presentteachings; and

FIG. 13 is a side view of a patient-specific guiding system according tovarious other exemplary embodiments of the present teachings.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses. Forexample, although the present teachings are illustrated for alignmentguides in knee surgery, the present teachings can be used for otherguides, templates, jigs, drills, rasps or other instruments used invarious orthopedic procedures.

The present teachings generally provide patient-specific alignmentguides and associated cutting guides for use in orthopedic surgery, suchas in knee arthroplasty, for example. The patient-specific alignmentguides can be used either with conventional or patient-specific implantcomponents prepared with computer-assisted image methods. Computermodeling for obtaining three dimensional images of the patient's anatomyusing MRI or CT scans of the patient's anatomy, the patient specificprosthesis components, and the patient-specific guides and templates canbe provided by various CAD programs and/or software available, forexample, by Materialise USA, Ann Arbor, Michigan.

The patient-specific alignment guides are generally formed usingcomputer modeling based on the patient's 3-D anatomic image and have aninner engagement surface that is made to conformingly contact and matcha three-dimensional image of the patient's bone surface (with or withoutcartilage or other soft tissue), by the computer methods discussedabove. The patient-specific alignment guides can include custom-madeguiding formations, such as, for example, guiding bores or cannulatedguiding posts or cannulated guiding extensions or receptacles that canbe used for supporting or guiding other instruments, such as drillguides, reamers, cutters, cutting guides and cutting blocks or forinserting pins or other fasteners according to a surgeon-approvedpre-operative plan. The patient-specific alignment guides can be used inminimally invasive surgery, and in particular in surgery with multipleminimally-invasive incisions. In one aspect, the cutting guides caninclude guiding cannulated or tubular legs that can be received in theguiding bores of the alignment guides for cutting therethrough, asdiscussed below.

The patient-specific alignment guides and the associated cutting guidescan be structured to provide or define a clearance for tendons,ligaments or other tissues associated with the joint. In the exemplaryillustrations of FIGS. 1-13, various alignment guides and cutting guidescan be structured to have specific geometric features for avoiding atendon associated with the femur or tibia of the knee joint, whileenabling the placement of a cutting tool (e.g., blade, drill bit, etc.)as close to the tendon as determined by the surgeon and whilemaintaining an alignment relative to the joint as determined by thepre-operative surgical plan.

Furthermore, the patient-specific alignment guides can include one ormore openings and/or guiding receptacles, the precise location of whichare determined on the basis of a pre-operative surgical plan forlocating alignment pins and assisting in locating drilling and/orcutting instruments for resecting and shaping the joint for receiving aprosthetic implant, as described in commonly-owned, co-pending in U.S.patent application Ser. No. 11/756057, filed on May 31, 2007,incorporated herein by reference.

Referring initially to FIG. 1-3 an exemplary embodiment of apatient-specific guiding system 10 will be initially discussed. Thesystem 10 can be used for cutting a portion of an anatomical feature 11of a patient. It will be appreciated that the system 10 can be used forcutting any suitable anatomical feature 11, such as a bone. Also, itwill be appreciated that the system 10 can be used to prepare theanatomical feature 11 for any suitable purpose (e.g., for implantationof an artificial knee joint or other prosthetic device).

As shown in FIG. 1-3, the guiding system 10 can include patient-specificalignment guide 12. The guide 12 can be made out of any suitablematerial, such as a rigid polymeric material. The shape of the guide 12can closely conform to a surface of the anatomical feature 11 as will bediscussed below. Also, as will be discussed, the guide 12 can locate andalign a cutting tool 14 (FIG. 3) or other instruments such as drills,punches, and the like at a predetermined location relative to theanatomical feature 11. As such, the guide 12 locates and aligns thecutting tool 14 for accurate cutting of the anatomical feature 11. Itwill be appreciated that the cutting tool 14 can be of any suitabletype, such as a power tool or a manually operated tool.

The alignment guide 12 can include a first portion 16 (FIGS. 1-3). Thefirst portion 16 can have a relatively thin, plate-like shape. The firstportion 16 can include an outer surface 18, an inner surface 20 that isopposite the outer surface 18, and a side surface 22 that extends aboutthe periphery of the first portion 16.

Moreover, the alignment guide 12 can include a second portion 24 (FIGS.1-2). The second portion 24 can have a relatively thin, plate-likeshape. The second portion 24 can include an outer surface 26, an innersurface 28 that is opposite the outer surface 26, and a side surface 30that extends about the periphery of the second portion 24.

The second portion 24 can be removably connected to the first portion16. The second portion 24 can be removably connected to the firstportion 16 in any suitable fashion. For instance, as shown in FIG. 1,the alignment guide 12 can include a dovetail coupling 32 that removablycouples the first and second portions 16, 24. More specifically, theside surface 22 of the first portion 16 can include male components 34of the dovetail coupling 32, and the side surface 30 of the secondportion 24 can include corresponding female components 36 of thedovetail coupling 32. The male components 34 can be removably receivedwithin the female components 36 to removably couple the first and secondportions 16, 24. Accordingly, as will be discussed, the second portion24 can be easily removed from the first portion 16 to thereby expose thearea of the anatomical feature 11 that will be cut.

As shown in FIG. 2, the first and second portions 16, 24 of the guide 12can be coupled to the anatomical feature 11. The first and secondportions 16, 24 can be configured to be coupled to any suitableanatomical feature 11, such as a femur 38 or other bone.

Specifically, as shown in FIG. 2, the inner surface 20 of the firstportion 16 can be patient-specific, such that the inner surface 20closely conforms in shape to a first surface 40 (e.g., an anteriorsurface) of the femur 38 of the individual patient. Likewise, the innersurface 28 of the second portion 24 can be patient-specific, such thatthe inner surface 28 closely conforms in shape to a second surface 42(e.g., a distal end surface) of the femur 38 of the individual patient.Thus, the inner surfaces 20, 28 can each have three dimensional contoursthat substantially match the first and second surfaces 40, 42,respectively, and the first and second portions 16, 24 can nest with thefirst and second surfaces 40, 42. As stated above, the inner surfaces20, 28 can be shaped according to a computerized model formulated froman imaging process (e.g., MRI, etc.). Accordingly, the guide 12 can havea customized fit against the femur 38, and cutting of the femur 38 canbe performed accurately, according to the individual dimensions of thepatient's anatomy.

Furthermore, the first portion 16 can include one or more through holes44 that extend from the outer surface 18 to the inner surface 20. Theprecise location of the through holes 44 can be determined on the basisof the pre-operative surgical plan discussed above. Also, the system 10can include one or more corresponding pins 46 as shown in FIGS. 1 and 2.The pins 46 can extend through corresponding ones of the holes 44 andinto the femur 38 to thereby fixedly couple the first portion 16 to thefemur 38. It will be appreciated that the second portion 24 can befixedly coupled to the femur 38 only through the pins 46. Accordingly,the second portion 24 can be easily removed from the first portion 16and from the femur 38 simply by de-coupling the second portion 24 fromthe first portion 16, without having to remove other hardware.

Still further, the first portion 16 can include a guide surface, such asan opening 48, as shown in FIGS. 1-3. The precise location of theopening 48 can be determined on the basis of the pre-operative surgicalplan discussed above. As will be discussed, the opening 48 can receivethe cutting tool 14 (FIG. 3) to guide the cutting tool 14 toward thefemur 38 to cut the femur 38 accurately. For example, the opening 48 canbe a slot 50 with a straight longitudinal axis that extendssubstantially parallel to the coupling 32. Also, the slot 50 can extendentirely through the first portion 16 from the outer surface 18 to theinner surface 20. As such, the slot 50 can receive and guide a saw blade52 (FIG. 3) for making a substantially planar cut along a cutting plane54. For instance, the cutting plane 54 can be defined on a horizontalplane of the femur 38 to form a distal femoral cut.

It will be appreciated that the opening 48 in the first portion 16 canhave any suitable shape to receive and guide any suitable cutting tool14 other than a saw blade 52. For instance, the opening 48 can berounded in order to receive a drill bit and to guide the drilling ofholes in the femur 38. Also, the opening 48 can have any suitablelocation on the first portion 16 to guide cutting toward any portion ofthe anatomical feature 11. For instance, the surgeon can determine adesired location of the cutting plane 54 according to the computerizedmodel discussed above, and the opening 48 can be located on the firstportion 16 such that the actual cutting plane 54 closely coincides withthe desired cutting plane 54.

It will also be appreciated that the side surface 22 or the outersurface 18 of the first portion 16 can be a guide surface for guidingthe cutting tool 14 or other instrument. For instance, the cutting tool14 or other instrument can abut against the side surface 22, and assuch, the cutting tool 14 can be aligned relative to the femur 38.Furthermore, the cutting tool 14 or other instrument can be supported onthe outer surface 18 to be aligned relative to the femur 38.

Thus, during use, the first and second portions 16, 24 of the guide 12can be coupled to the femur 38 that the inner surfaces 20, 28 nestagainst and engage the femur 38 as shown in FIG. 2. Because both thefirst and second portions 16, 24 nest against the femur 38, and becausethe inner surfaces 20, 28 nest against a relatively large surface areaof the femur 38, the guide 12 can position and align itself relative tothe femur 38 in a highly accurate fashion.

Once the guide 12 is coupled to the femur 38, the second portion 24 canbe removed from the first portion 16 (FIG. 3) by pulling the secondportion 24 away from the femur 38. This, in turn, exposes the secondsurface 42 of the femur 38 and allows for better visibility of the femur38 before cutting. For instance, once the second portion 24 has beenremoved, the surgeon can visually confirm that the opening 48 will allowthe saw blade 52 to cut the femur 38 at a desired location. Furthermore,if the surgeon discovers that the cutting plane 54 needs to be moved,the surgeon can discard the guide 12 and form a new guide 12 with anopening 48 at a different, more desirable location.

Then, the saw blade 52 can be introduced into the opening 48, and thesaw blade 52 can cut the femur 38 along the cutting plane 54. Asdiscussed above, the opening 48 can guide movement of the saw blade 52toward the femur 38 during this cutting operation. Also, since thesecond portion 24 has been removed, the surgeon can have bettervisibility of the femur 38 while being cut.

Accordingly, the guide 12 provides a convenient and accurate means foraligning and guiding the saw blade 52 relative to the femur 38 forcutting operations. For instance, separate components, such as separatecut blocks can be unnecessary for cutting since the first portion 16 ofthe guide 12 includes the opening 48. Moreover, the guide 12 need not befully removed in order to cut the femur 38. Also, the guide 12 providessubstantial visibility of the femur 38 during cutting.

Referring now to FIG. 4, another exemplary embodiment of thepatient-specific alignment guide 112 is shown for use within apatient-specific guiding system 110. Features of the guide 112 thatcorrespond to the guide 12 of FIGS. 1-3 are indicated with correspondingreference numerals increased by 100.

The guide 112 can be substantially similar to the guide 12 shown inFIGS. 1-3, except that the first and second portions 116, 124 can beremovably coupled to each other via a scored coupling 132. Morespecifically, the guide 112 can have a scoring line 133 (e.g., a shallowgroove) that extends continuously about the guide 112. The scoring line133 weakens the coupling 132 such that the guide 112 can be easilybroken along the scoring line 133, for instance, by manually rotating orpulling the second portion 124 relative to the first portion 116. Thus,in order to remove the second portion 124 from the first portion 116,the surgeon can break the second portion 124 away from the first portion116 along the scoring line 133. Thus, the coupling 132 can allow foradded convenience when removing the second portion 124 from the firstportion 116.

Referring now to FIGS. 5 and 6, another exemplary embodiment of thepatient-specific alignment guide 212 is shown for use within apatient-specific guiding system 210. Features of the guide 212 thatcorrespond to the guide 12 of FIGS. 1-3 are indicated with correspondingreference numerals increased by 200.

The guide 212 can be substantially similar to the guide 12 shown inFIGS. 1-3, except that the first and second portions 216, 224 can beremovably coupled to each other via a pinned coupling 232. Morespecifically, the first portion 216 can include one or more pins 260that extend upward from the outer surface 218. The pins 260 can be fixedto the first portion 216. Also, the second portion 224 can includecorresponding through holes 262 that removably receive the respectiveones of the pins 260. Accordingly, the coupling 232 can allow for addedconvenience when removing the second portion 224 from the first portion216.

Referring now to FIGS. 7 and 8A, another exemplary embodiment of thepatient-specific alignment guide 312 is shown for use within apatient-specific guiding system 310. Features of the guide 312 thatcorrespond to the guide 12 of FIGS. 1-3 are indicated with correspondingreference numerals increased by 300.

As shown in FIG. 7, the first and second portions 316, 324 of the guide312 can be substantially similar to the first and second portions 16, 24of the guide 12 shown in FIG. 1; however, the first portion 316 does notinclude the opening 22. Instead, the system 310 includes a separatecutting block 366 (i.e., cutting guide) that includes an opening 368 orother guide surface for guiding and aligning a cutting tool 314 relativeto the femur 338. The opening 368 can be a slot, a rounded hole, anedge, or of any other type, similar to the embodiments discussed above.Also, the cutting block 366 can include one or more through holes 369that removably receive the pin(s) 346 of the guide 312 to removablycouple the cutting block 366 to the first portion 316 of the guide 312.It will be appreciated, however, that the cutting block 366 can beremovably coupled to the first portion 316 in any suitable fashion(e.g., a dovetail coupling, etc.)

Thus, during use, the guide 312 can be fitted to the femur 338 similarto the embodiments discussed above. Then, the second portion 324 of theguide 312 can be removed. Next, the cutting block 366 can be supportedon the outer surface 318 (i.e., the guide surface) of the first portion316 to align the cutting block 366 relative to the femur 338. Thecutting block 366 can be removably coupled to the first portion 316 suchthat the cutting block 366 is supported on the femur 338 by the firstportion 316. As such, the opening 368 can be located and alignedrelative to the femur 338 due to the attachment of the cutting block 366to the first portion 316 of the guide 312. Subsequently, the cuttingtool 314 can be introduced into the opening 368, and the opening 368 canguide the cutting tool 314 toward the femur 338 for cutting the femur338 along the cutting plane 354.

Furthermore, as shown in FIG. 8B, the cutting block 366 can be removedfrom the first portion 316, and a secondary cutting block 366′ (e.g., aFour-in-One cutting block commercially available from Biomet of Warsaw,Indiana) can be removably coupled to the first portion 316 forperforming additional cutting of the femur 338. More specifically, thesecondary cutting block 366′ can include through holes 369′ thatremovably receive the pins 346 such that the first portion 316 alignsthe secondary cutting block 366′ at a predetermined position relative tothe femur 338. The secondary cutting block 366′ can also include arespective opening 368′ for guiding the cutting tool 314 while cuttingalong a secondary cutting plane 354′. For instance, the secondarycutting block 366′ can be used for forming an anterior femoral cut, aposterior femoral cut, or a femoral chamfer cut.

Also, in some embodiments, the pins 346 and/or the first portion 316 canobstruct this additional cutting of the femur 338. Thus, as shown inFIG. 8B, after the secondary cutting block 366′ is coupled to the firstportion 316 via the pins 346, one or more secondary pins 346′ can beused to couple the secondary cutting block 366′ to the femur 338. Next,the pins 346 and the first portion 316 can be removed from the femur338, leaving the secondary cutting block 366′ coupled to the femur 338via the secondary pins 346′. Then, the cutting tool 314 can be receivedin the opening 368′ to cut the femur 338 along the secondary cuttingplane 354′, and the secondary pins 346′ are unlikely to obstruct thecutting tool 314. Thus, the guide 312 can be versatile for supportingand aligning a plurality of cutting blocks 366, 366′ relative to thefemur 338.

Referring now to FIG. 9, another exemplary embodiment of thepatient-specific system 410 is shown. Features of the system 410 thatcorrespond to the system 310 of FIGS. 7-8B are indicated withcorresponding reference numerals increased by 100.

The system 410 is substantially similar to the system 310 of FIGS. 7-8B,except that the cutting block 466 is removably coupled to the firstportion 416 of the guide 412 via a snap-fit coupling 432. For instance,the cutting block 466 can include one or more openings 470, each with aplurality of resilient members 472. For instance, the openings 470 canbe rounded and can have a shape that corresponds to the pins 446. Theresilient members 472 can be spaced apart at a width W that is less thana width W′ of one of the pins 446.

Thus, to removably couple the cutting block 466 to the guide 412, thecutting block 466 is moved toward the pins 446, and the resilientmembers 472 resiliently deflect to allow passage of the respective pin446 into the respective opening 470. Then, to remove the cutting block466, the resilient members 472 can resiliently deflect to allow passageof the respective pin 446 out of the respective opening 470. Thus, thesnap-fit coupling 343 can allow for quick and convenient coupling andde-coupling of the cutting block 466 and the guide 412.

Referring now to FIG. 10, another exemplary embodiment of thepatient-specific system 510 is shown. Features of the system 510 thatcorrespond to the system 310 of FIGS. 7-8B are indicated withcorresponding reference numerals increased by 200.

The system 510 is substantially similar to the system 310 of FIGS. 7-8B,except that the system 510 can include one or more spacers 578 a, 578 bthat can be disposed between the cutting block 566 and the first portion516 of the guide 512. The spacers 578 a, 578 b can be relatively flatand thin (e.g., 1 mm thickness) plates. The spacers 578 a, 578 b canspace the cutting block 566 and the guide 512 apart at a predetermineddistance. For instance, before cutting, the surgeon may wish to adjustthe position of the opening 568 relative to the femur. Thus, the surgeoncan include one or more spacers 578 a, 578 b between the cutting block566 and the first portion 516 to move the opening 568 the desireddistance relative to the femur. In the embodiment shown, for instance,the surgeon can include additional spacers 578 a, 578 b in order to movethe opening 568, and thus the cutting plane, distally along the femur.Thus, the system 510 can be modular and versatile for cutting theanatomy at desired locations.

Moreover, as shown in FIG. 10, the cutting block 566 and the firstportion 516 of the guide 512 can be removably coupled via a magneticcoupling 532. For instance, the first portion 516 can include one ormore magnets 574, and the cutting block 566 can also include one or morecorresponding magnets 576 that are magnetically attracted to the magnets574. In other embodiments, only the magnets 574 are included, and themagnets 574 are magnetically attracted to the material of the cuttingblock 566. In other embodiments, only the magnets 576 are included, andthe magnets 576 are magnetically attracted to the material of the firstportion 516. It will be appreciated that the magnetic attraction of themagnets 574, 576 is sufficient enough to couple the cutting block 566,the spacers 578 a, 578 b, and the first portion 516 if the spacers 578a, 578 b are included. Accordingly, the magnetic coupling 532 canprovide for convenient coupling and de-coupling of the cutting block 566and the first portion 516.

Referring now to FIG. 11, another exemplary embodiment of the guide 612is illustrated. Features of the guide 612 that correspond to the guide12 of FIGS. 1-3 are indicated with corresponding reference numeralsincreased by 600.

As shown in FIG. 11, the guide 612 is patient-specific and is shaped toconform to a tibia 680 of the patient. As such, the guide 612 includesthree dimensional contoured surfaces that nest against and conform tothe tibia 680, similar to the embodiments discussed above. The guide 612can include a first portion 616 that fits on an anterior surface of thetibia 680 and a second portion 624 that fits on a proximal end surfaceof the tibia 680. The guide 612 can be used for cutting the tibia 680along a cutting plane 654 (e.g., a horizontal tibial cut).

The guide 612 can also include a laser 682. In some embodiments, thelaser 682 is embedded within the guide 612; however, in someembodiments, the laser 682 can be removably coupled to the guide 612.The laser 682 can be of any suitable type, and the laser 682 can emitlight along a path 684 to identify a reference plane for use in aligninga guide surface of the guide 612 and for confirming that the guidesurface is at a desired location relative to the tibia 680. As such, theemitted light can indicate where the cutting tool will cut the tibia 680prior to the cutting operation in order to confirm that the tibia 680will be cut at a desired location.

For instance, the reference plane indicated by the laser 682 can bedirected along a path 684 that is substantially perpendicular to thelongitudinal axis of the opening 648. Since the axis of the opening 648defines the cutting plane 654, the path 684 of the light becomessubstantially perpendicular to the cutting plane 654.

Thus, during use, the guide 612 can be coupled to the tibia 680 asdescribed above with respect to FIGS. 2 and 3. Next, the laser 682 canbe operated to emit light along the path 684. For instance, the laser682 can emit a dot of light that is reflected off of a reference point(e.g., one of the metatarsals 686) of the patient. If the light issubstantially centered on the reference point, (e.g., the secondmetatarsal 686), the surgeon knows that the cutting plane 654 issubstantially perpendicular to the major axis of the tibia 680. If thelight is spaced apart from the reference point, the surgeon knows thatthe cutting plane 654 may need to be adjusted. Other reference pointsother than the second metatarsal 686 can be used to confirm that thecutting plane 654 is properly aligned relative to the tibia 680 as well.Accordingly, the guide 612 allows for convenient and accurateconfirmation of the alignment of the cutting plane 654 before cutting isperformed.

It will be appreciated that the laser 682 can be directed along any path684 relative to the guide 612. For example, the reference planeindicated by the path 684 of the laser 682 can be at a positive, acuteangle relative to the longitudinal axis of the opening 648 (i.e., at apositive, acute angle relative to the cutting plane 654). This may beuseful, for instance, for indicating specific anatomy that is disposedat an angle relative to the cutting plane 654 and/or for adjusting thecutting plane 654 relative to that anatomy.

Referring now to FIG. 12, another exemplary embodiment of the guide 712is illustrated. Features of the guide 712 that correspond to the guide612 of FIG. 11 are indicated with corresponding reference numeralsincreased by 100. As before, the guide 712 can include three-dimensionalcontoured surfaces that nest against and conform to the tibia 780.

As shown in FIG. 12, the laser 782 can include a first end 783 and asecond end 785. The laser 782 can be coupled to the first portion 716 ofthe guide 712 such that the first and second ends 783, 785 are bothangled toward the tibia 780. Also, the first and second ends 783, 785can emit light in a straight line that is disposed within the cuttingplane 754. As such, the surgeon can use the laser 782 to illuminate aproposed cutting plane/line on the tibia 780. Thus, the surgeon canconfirm that the cutting plane 754 is at a desired location relative tothe tibia 780.

Referring now to FIG. 13, another exemplary embodiment of the system 810is illustrated. Features of the system 810 that correspond to the system610 of FIG. 11 are indicated with corresponding reference numeralsincreased by 200.

As shown in FIG. 13, the laser 882 can be removably coupled to thecutting block 866. For instance, the system 810 can include a fixture890 that removably couples to both the laser 882 and the cutting block866. In other embodiments, the fixture 890 can directly couple the laser882 to the first portion 816 of the guide 812.

The laser 882 can emit light in a line that is directed along a paththat is substantially perpendicular to the cutting plane 854. Thus,similar to the embodiment of FIG. 11, the laser 882 can help the surgeonto confirm that the cutting plane 854 is at a desired location relativeto the tibia 880.

In summary, the patient-specific guiding system 10-810 discussed hereinprovides for accurate and convenient alignment of the cutting tool14-814 relative to the anatomy because the guide 12-812 has threedimensional surfaces that closely conform to respective surfaces of theanatomy of the patient. Furthermore, the guide 12-812 can include firstand second portions that are removably coupled (e.g., via a dovetailcoupling 32, a pinned coupling 232, a scored coupling 132, a magneticcoupling 532, a snap-fit coupling 432, etc.) such that the anatomy has ahigh degree of visibility before and during cutting. Moreover, the guide12-812 can include an opening 48-848 or other guide surface that guidesthe cutting tool 14-814 for accurate and convenient cutting. Also, insome embodiments, the guide 12-812 can removably couple to a separatecutting block 366, 466, 566, 866 (e.g., via a dovetail coupling 32, apinned coupling 232, a scored coupling 132, a magnetic coupling 532, asnap-fit coupling 432, etc.), and the cutting block 366, 466, 566, 866can include the opening 368, 468, 568 for guiding the cutting tool 314,414, 514 for accurate cutting. As such, the system 10-810 can allow theanatomy to be cut more accurately, and a prosthetic device can be bettercustomized for the patient.

The foregoing discussion discloses and describes merely exemplaryarrangements of the present teachings. Furthermore, the mixing andmatching of features, elements and/or functions between variousembodiments is expressly contemplated herein, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one embodiment may be incorporated intoanother embodiment as appropriate, unless described otherwise above.Moreover, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the present teachings asdefined in the following claims.

1. A patient-specific guiding system for guiding an instrument relativeto a portion of an anatomical feature of a patient, the patient-specificguiding system comprising: a patient-specific guide having: a firstportion having a first patient-specific inner surface that conforms to afirst surface of the anatomical feature and an outer surface oppositethe first patient-specific inner surface, the first portion including aguide surface for use in guiding the instrument relative to theanatomical feature; and a second portion having a secondpatient-specific inner surface that conforms to a second surface of theanatomical feature and an outer surface opposite the secondpatient-specific inner surface, the second portion being removablyconnected to the first portion; wherein the first and secondpatient-specific inner surfaces each have a three dimensional contourthat nests and closely conforms to the first and second surfaces,respectively, of the anatomical features, to align the guide relative tothe anatomical feature.
 2. The patient-specific guiding system of claim1, wherein the second portion is removably connected to the firstportion by at least one of a dovetail coupling, a pinned coupling, ascored coupling, a magnetic coupling, and a snap-fit coupling.
 3. Thepatient-specific guiding system of claim 1, further comprising acoupling mechanism that couples the first portion directly to theanatomical feature, and wherein the second portion is coupled to theanatomical feature only through the coupling mechanism, by coupling withthe first portion.
 4. The patient-specific guiding system of claim 1,wherein the guide surface is an opening that receives the instrument. 5.The patient-specific guiding system of claim 1, further comprising alaser coupled to the guide that emits a light that identifies areference plane for use in aligning the guide surface relative to theanatomical feature.
 6. The patient-specific guiding system of claim 5,wherein the reference plane is substantially perpendicular to a cuttingplane of the instrument, the instrument cutting the portion of theanatomical feature along the cutting plane.
 7. The patient-specificguiding system of claim 5, wherein the reference plane lies in a cuttingplane of the instrument, the instrument cutting the portion of theanatomical feature along the cutting plane.
 8. The patient-specificguiding system of claim 1, further comprising a cutting guide having acutting surface that guides a cutting tool for cutting the anatomicalfeature, the guide surface removably supporting the cutting guide toalign the cutting guide relative to the anatomical feature.
 9. Thepatient-specific guiding system of claim 8, wherein the cutting guide isremovably connected to the first portion by at least one of a dovetailcoupling, a pinned coupling, a scored coupling, a magnetic coupling, anda snap-fit coupling.
 10. The patient-specific guiding system of claim 8,further comprising a spacer that is removably interposed between thecutting guide and the first portion to space the cutting guide and thefirst portion apart at a predetermined distance.
 11. Thepatient-specific guiding system of claim 1, further comprising asecondary cutting guide that guides a cutting tool for cutting theanatomical feature, and a secondary coupling mechanism that couples thesecondary cutting guide to the anatomical feature, the guide surfaceremovably supporting the secondary cutting guide to align the secondarycutting guide relative to the anatomical feature, the first portionbeing removable from the anatomical feature while the secondary cuttingguide is coupled to the anatomical feature.
 12. A guiding systemcomprising: a first portion configured to extend along a surface of abone, the first portion comprising: at least one fixation featuredisposed on the first portion; and a first coupling feature; and asecond portion configured to engage a portion of the bone to beresected, the second portion comprising: a second coupling featureconfigured to interface with the first coupling feature; and an interiorsurface that is patient-specific to conform to an anatomical surface ofthe portion of the bone to be resected; wherein the interior surface isconfigured to engage the anatomic surface to position the at least onefixation feature at a patient-specific location on the bone; and whereinthe second portion is separable from the first portion at the interfacebetween the first and second coupling features.
 13. The guiding systemof claim 12, wherein first portion is patient-specific to conform to thesurface of the bone.
 14. The guiding system of claim 12, wherein thefirst portion further comprises a first cutting guide feature locatedbetween the at least one fixation feature and the first couplingfeature, the first cutting guide feature comprising an openingpositioned to engage a portion of the bone to be cut.
 15. The guidingsystem of claim 14, wherein the second portion is separable from thefirst portion such that the portion of the bone to be resected isvisible when a cutting tool is inserted in the first cutting guidefeature.
 16. The guiding system of claim 12, further comprising a thirdportion comprising: a third coupling feature configured to join with thefirst coupling feature; and a second cutting guide feature extendingthrough the third portion; wherein the second cutting guide featureextends beyond an outer perimeter of the first portion when the firstand third coupling features are engaged.
 17. The guiding system of claim12, further comprising a spacer positioned between the first couplingfeature and the second coupling feature.
 18. The guiding system of claim12, further comprising a pin, wherein the at least one fixation featurecomprises a through-bore configured to receive the pin to fixedly couplethe first portion to the bone.
 19. A guiding system comprising: a firstportion configured to extend along an anterior surface of a femur, thefirst portion comprising: at least one through-bore extending throughthe first portion; a distal side surface; and a cutting guide slotextending through the first portion and disposed between the at leastone through-bore and the distal side surface; and a second portionconfigured to engage a distal end of the femur, the second portioncomprising: a proximal side surface configured to join with the distalside surface; and an interior surface having a three-dimensional contourthat nests and closely conforms to the distal end of the femur; whereinthe first and second portions are configured to position the cuttingguide slot at a patient-specific location on the anterior surface of thefemur.
 20. The guiding system of claim 19, wherein the second portion iscouplable to the femur only through joining of the distal side surfaceand the proximal side surface.